"The Vampire Diaries" cast and crew at a celebration for the series' 100th episode Thursday. Twitter: @julieplec

Ian Somerhalder and Nina Dobrev put aside rumors that they have rekindled their off-screen romance this week to celebrate the 100th episode of their hit CW series, “The Vampire Diaries,” Thursday.

Following their friendly onstage appearance (and surprising televised kiss!) at the People’s Choice Awards Jan. 8, the “TVD” actors once again showed they’re on good terms by celebrating their supernatural series' milestone with a cast party Thursday night. “100 episodes of #TVD star right now… Tvd family viewing party at my Casa [sic],” Dobrev, 25, shared on her WhoSay account. The message was posted alongside an image of Somerhalder, 35, joined by their co-stars Kat Graham and Michael Malarkey and executive producer Julie Plec, enjoying the get-together in celebration of the show’s season five midseason premiere episode, “500 Years of Solitude.”

Fans of the supernatural series have since responded to the post, praising not just Somerhalder and Dobrev, but all of the show's cast for their close bond. “That’s just incredible how close and sweet you all are, you all should be proud of all yourselves. This is a big accomplishment and you deserve it,” posted one fan Thursday.

Somerhalder and Dobrev, dubbed “Nian” by the series' fan base, have been the subject of relationship rumors in recent weeks. CelebDirtyLaundry.com reported Monday that the former couple is allegedly slowly and "privately" rekindling their three-year romance after splitting in May. “They’re both doing their best to keep it quiet," a source told the site, adding, "They’re not sure if they’re going to go back into full dating mode, especially since they’re still on good terms and don’t want to ruin their existing friendship."

Will the “TVD” fan base every seen a Nina-Ian reunion off-screen? According to the insider, that depends on their personal progress as a couple and “how crazy the focus on them is” as the show continues into its fifth season.